Container



May 13, 1941. R. E. LOWEY CONTAINER 3 Sheets-Sheet 1 Filed Jan. 21, 1939 May 13, 1941. R. E. LOWEY 2,241,710

- CONTAINER Filed Jan. 21, 1939 5 Sheet-Sheet 5 I jiverzz azi' figy lowqy Patented May 13, 1941 comma BoyE. Lowey, Evanston, 111., assignor to Container Corporation of America, Chicago, 11].. a

corporation of Delaware Application January 21, 1939, Serial N6. 252,079

9 Claims. (Cl. 229-14) The present invention relates to container'constructions. In particular, the present invention relates to lined containers of tray form arranged to have the open end thereof sealed by a lined closure element. v

One object of the invention is to. provide an eflicient container of tray form having an interior lining element extending also over a portion of the exterior of the container to afford a double sealing surface for a closure element arranged to contact both the interior and exterior of the container adiacent its open end.

Another object of the invention is to provide acontainer blank so formed that when a liner sheet has been applied thereto on one side only and the blank folded to form the container a portion of the liner will extend in a substantially unbroken condition around the upper exterior portion of the container to provide av sealing surface on the exterior.

'Another object of the invention is to provide an efficient form of container closure having a liner applied thereto with parts on the closure arranged to be sealed both against the upper interior and upper exterior parts of a container.

A further object of the invention is to provide a container element and recessed closure element having a thermoplastic surfaced liner applied to both elements to enable the closure element to be effectively sealed to the container element by suitable application of heat and pressure.

Additional objects will become apparent as the description proceeds.

In the drawings:

Fig. 1 is a perspective view of a container constructed in accordance with the present invention, showing the containerwith a closure element assembled therewith;

Fig. 2 is a perspective view of the tray portion of the container illustrating the tray as it would:

appear with one of the end flaps bent away from the end wall; 1

Fig. 3 is a fragmentary sectional view 'taken 'along line 38 of Fig. 1, illustrating the manner Qthe tray part of the container and illustrating a lining element attached thereto;

Fig. 6 is a plan view of the tray element, similar to Fig. 5, except showing the reverse side of the blank and showing the side extension flaps as glued in place against the outside of the blank;

Figs. 7, 8 and 9 are transverse sectional views showing the sequence of steps according to one method of sealing the container; and

10 is a transverse sectional view illustrating an intermediate position of the closure element with respect to the tray element, according to a somewhat modified method of sealing the container.- I

The present invention provides a container whichis particularly adaptable for use in connection with the packaging of food products in frozen condition where an important consideration is to retain to a maximum extent the original moisture in the food product at the time of packaging. The container of the present invention accordingly comprises preferably a tapered tray portion interiorly lined with a tough, impervious layer or-sheet of flexible material, such as Cellophane or Pliofllm, with certain portions of the lining material disposed on the outside of the tray along its upper edges. A closure is employed which. also has a lining arranged to contact the lined surface of the tray and to be sealed thereto.

Referring more particularly to the drawings, the tray part of the container is indicated as a whole at 5 and the closure part is indicated as a'whole at 6. The tray part and closure part for the purpose of securing the side walls 8, 8

and side wall end flaps. byscore lines Ha, lid

The score lines defining the side and end panels 9, 8 in tray forming relation. The manner of securing the end flaps III, III in relation to the end panels 9, 9 will be more fully pointed out as the description proceeds.

The blank of the tray part of the container is preferably provided with portions which are adapted to be folded back and secured to-the outer surface of. the tray as it appears in its set-up condition. For this purpose extension flaps II, II are provided along the outer edges of the side walls 8, 8 and similar extension flaps l2, I! are provided along the outer edges of each of the end flaps l0,- ID. The flaps II, II and l2, l2 are defined from their attached side wall and a, l2a. panels 8 and end panels 8 from the bottom panel are indicated respectively at ta, 8a and 9a, 9a.

The extension flaps H and ii are, in the present instance, formed so as to be integrally connected to each other at least over a portion of their width, as indicated at l3, 13, this being for the purpose of providing a smooth outer rim adjacent the top edge of the tray part of the container.

The tray of the present invention is preferably made tapered so that the trays can be set up at the box plant, then nested for shipment. For this purpose, both the sides and ends of the container are somewhat flared so as to be longer at the top edges than at the bottom. In order to provide for outwardly fiaredside walls the score lines M, It defining the ends of the side walls are impressed so as to be divergent outwardly of the blank, See Fig. 5. Outwardly flaring endwalls are provided in the present instance by so forming the side wall end flaps that when their edges meet centrally of the end of the tray the edges along the score lines l4, M will diverge upwardly,

as indicated in Fig. l. This-relationship not only tends to properly control the shape of the ends of the tray, but at the same time, insures smooth, outer portions at the upper edges of theend walls.

In practice, the tray is preferably set up by using a form about which the sides and ends are folded before securing the walls in fixed relationship. The use of a form tends to insure the proper positioning of the flaps III, III with their edges abutting.

The end panels 9, 9 are preferably formed so that their lateral edges 3b, 9b will be spaced from the interior corners of the tray. See Figs. 2 and 5. This spacing of the edges from the corners eliminates any possible interference with the proper positioning of the side walls, and gives the further advantage of a somewhat greater area for flaps Ill, Ill than would be the case if the panel 9 was shaped to accurately fit the cdrners of the tray.

The ends of the tray are preferably formed of exactly the same height as the side walls. For

this purpose the score line He, separating the extension flap from the main portion of flap l0,

extends in an inwardly deflected direction. This score line will thus be brought into substantial registry with the upper edge of the end wall 9 when the tray has been set up.

The side wall end flaps Ill are each preferably provided with an extended portion 15 projecting a substantial distance beyond the center line of the end 'wall when the tray is in set-up form. When adhesive is applied to the portions l5, l5 and these portions brought into overlapping position, after setting up the tray, the tray may thus be secured in such position.

One convenient method is to applyadhesive to each part l5,as indicated at I50, l5a on the same face of the blank and thereafter bring the parts l5, l5 together in setting up the tray.; Onead; hesived surface will engage against the outer surface of panel 9 and the other adhesived surface will engage against the back of the flap III which the lower edge of portion l2 on the opposite flap I.

edges of the tray. From the integral parts It to the outer edges of the flaps there are provided notched-out. portions Ila. The width of the notches is such asito cause the edges ofthe flaps to be spaced somewhat back of the corners of the tray, as shown in Figs. 1 and 2.

Since the score lines Ila and lla'are not in alignment it is apparent that when the flaps II and l2, l2 arefolded over and secured against the side wall and side wall end flaps respectively, the adjacent ends of the flaps H and I! will overlap one over the other. The tendency to overlap, however, is not sufllcient to completely disrupt the material of the Joining portion l3, due to the flexibility and elasticity of the folding paperboard used in the manufacture of the container, 50 that in practice this joining section will remain substantially intact when the tray is placed in set-up condition. In this way there is provided a smooth upper edge portion at the corners of the tray.

The tray and closure, according to the present invention, are each provided with an interior lining of impervious material. The lining material is preferably applied to the blanks while in fiat form.

In 'the application of the liner to the tray blank, in the present instance, suitable lines or bands of adhesive are applied to the blank as indicated by stippled portions I]. The liner sheet i8 is then applied to the tray blank andthe adhesive is allowed to set. The liner sheet is preferably of generally rectangular shape and is of such a width as to not extend substantially beyond the tensions H and i2. Thelenathvof the liner is such that it will extend substantially to the outer edges of panels 8, 9. It isalso particularly desirable to substantially register the edge of the liner sheet with the point on the edges of flaps l0,. 10, where the score line lla'meets such edges. It is to be noted that the extensions l5, IE will thus remain uncovered by the liner sheet,'this permitting application of adhesive directly thereto, as above described.

The next step in the preparation of the blank is to fold the extensions II and l2, l2 against the under side of the tray blank so as to conveniently locate a strip of liner material on the upper exterior portions of the tray. For this purpose-the under side of the blank has applied to it a' band of adhesive along the edges of extensions H and l2, l2 and these extensions are be applied only to one extendedportionl5 and this portion would be brought into a position over the other flap 10. In this manner there would be adherence between the naps only and no adherence between the inner flap l3 and theend of next bent over and down upon the side wall and side wall end flaps and secured'in such position,

see Fig. 6. The blank is then ready to be set up into tray form. l V. Setting up of the tray part may conveniently be done on well known forms of machinery, one

form being known in the trade as the Brightwood pail machine. Adhesive is applied to each extension l5, as above stated. The end panels 8, I are next brought to raised position. At the same time the side walls are swung'upwardly and inwardly and the flaps l0, III are afterward folded to he one against the other on the outer surface ,of

panel 9. At each end of the panel 8. atriangular portion-of the liner, indicated at Ida, is left unsecured and free totmove away from the underlying laterai edges of the blank, that is, along the extion is brought to a position against the outer extends beyond its companion part at each end surface of. the panel 9 when the flaps l0, ID are in their final position, as indicated in Fig. 2.

It is apparent that the tray, as constructed and assembled, will have a complete unbroken interior lining together with a strip of lining material entirely around the outside of the tray adjacent the upper edges thereof. As the meeting edges of the flaps l0, III are constructed to meet with accuracy and as the liner extends to such edges it is manifest that the outer strip of liner material will be substantially unbroken, the only joints being at these meeting edges.

It is to be noted at this point that the shaping of the end wall flaps 9, 9-so that the edges of these flaps are spacedfrom the interior corners of the tray has the further advantage of insuring proper'folding of the liner between the panel 9 and the flaps l0, ill in the operationof setting up the tray. As previously stated the edge of the liner preferably is placed so as to accurately register with the edge qf the flap. l0. It is accordingly important that this relationship of the edge of the liner with the edge of thefiap 9 be left undisturbed so that when the tray has been set up, the edges of the liner secured at the abutting edges of the flaps II, I! will form a tight and substantially unbroken joint. If the edges of panels 9 are formed to diverge outwardly to an extent suflicient to cause these edges to engage the comers of the tray there is. a tendency for the liner to become pulled away from the edge of the flap l0 where the score line l2a meets such edge due to the fact that the operation of swinging the panel! upwardly may be somewhat too far advanced relative to the upward swinging of the side walls 8 8- and the inward swinging of the flaps l0, III. In other words, there should be a isfactory to bring-the 'end'pan'els 9, land the sidewalls 8, 8 to -final raised position prior to be- .ginningithe inward swinging movement of the p l0, lllagainst such panels 9;

I The closure 6 of the containerwill-now be described- This closure; as-herein illustrated, comprises a main panel zliahaving end extension flaps 2|v and side-extension flaps 22 all defined from the main panelby score lines 20a, 20a..

The end extensions 2| are made in two parts Ila and 2 lb and theside extensions likewise are made in two parts 22a and 22b, both sets of parts being separated by score linesindicated at He. and Ho respectively. The score lines 2lc and 22c are made of suiiicient width'to accommodate multiple thicknessesof material between the parts 2la,

zlb and22a, 22b, as shown inFig. 3,and aswill presently be referred to in more detail.

The extension parts Ma and 22a are constructa .ed'of such lengths as to snuglyfit the upper in- ,terior portions of the container walls after the 1 panel 20 has been moved into the tray to a depth approximately equal to the width of the extension parts a and 22a. The score lines 2lc and 22ewill'then engageagains't the upper edges of the tray. The extension parts 2 lb and-22b may then be folded to lie on the outside of thetray. It

is to be noted that the extension part 2lb is.

a distance approximately equal to the diagonal thickness of the multiple layers of material at the corners of the tray.

In order to conform to the taper of the tray the ends of the extension parts are divergent outa wardly from the main panel as to the parts 2la and 22a and convergent outwardly from the main panel as to the parts 2 lb and 22b. 7

v A liner 24 of impervious sheet material is secured to the closure 6. This liner sheet is preferably of such size that it will lie within the confines of the closure parts. The liner sheet extends also over at least a substantial portion of the triangular area defined by the adjacent end edges of the closure flaps.

I The closure may have .a window opening closure element 25 formed in the main panel 20. This is provided by slitting a rectangular area around three sides and forming a weakened line 26 along the remaining side.

The lined surfaces are preferably adhesively held in place. For this purpose liquid glue substances may be employed, however, the preferred method of sealing .the lined surfaces together is to employ lining material having a thermoplastic surface. Lining material found to be suitable for this purpose may comprise thin cellulosic sheet material coated with suitable lacquers, resins, or rubber compounds, such as rubber hydrochloride or the liner may comprise a sheet which is inherently thermoplastic, such as sheets of rubber hydrochloride.

After the parts are folded into place, as above described, they are sealed together by applying appropriated degrees of heat and pressure. For this purpose heated elements are preferably 'employed forcefully pressed against the exterionof theextension flaps Zla and Main a' direction outwardly of the container and against the exterior surfaces of extensionflaps 21b and 22b in a direction inwardly of the container. -The' con- I tainer. as thus sealed is, ready for shipment to -market. I

A convenien and effective method *ofsealing the container will nowbe described. After the desiredjquantity. of food or other product has been delivered to the tray part of the container it is ready tosreceive the ,cover. Theiirst step is to place the closure in position as illustrated in Fig. 7 so that thepanel'lll is directly over the -top of the filledtray. The panel is then pushed into the'tray to a distance equal to the width of extension parts vzla, Haas illustrated in-Flg. 8. This causes the extension flaps to be bent upward along score lines 20a, 20a. The parts 2") and'22b are next bent-downward to lie against the upper exterior edge portions of ,the tray as illustrated in Fig. 9. I By these operations the lined surfacesofn-the extensions Zia; 2lb, 22a and 22b are 'broughtinto flatcontact respectively with the upper" interior and exterior lined surfaces of the I tray. 1

During the operation of'iitting the closure extension flaps around the upper edges of the tray walls the liner portions at the corners will become larger than part Ila and likewisepart 22b is longer than part22a.- Eachpart Nb and 22b of material in the corners,-

pleated or interfolde'd so as to {fit snugly into the tray corners. The spacing of the edges of the end panels 9 from the corners, as above referred portions of the folding movement of the flap extensions are efiected simultaneously with the movement of the main panel M to final position. For this purpose, suitable mechanism may be employed for initiating movement of the main panel is provided for swinging the parts 2|b and 22b.

relatively downward with respect to their attached parts 2la and 22a, respectively. At an intermediate step in the operation the closure parts in this method of sealing would assume a position substantially as illustrated in Fig. 10. This relative swinging movement of the parts 2 la and 22a is continued until such parts come to rest against the upper exterior portions of the tray, as illustrated in Fig. 9. The movement is preferably so controlled that the parts 2lb and 22b reach their final positions at substantially the same time as the panel 20 reaches its final downward movement. When the closure parts are thus brought into position with the parts 2 la and 22a bearing against the interior portion of. the tray and the parts 2m and 22!) hearing against the exterior portion of the tray, mechanism is then provided for applying pressure and heat to these parts for the purpose of softening the thermoplastic surface of the liner material on both the tray and the closure, whereby. the closure will be sealed to the tray on both interior and exterior surfaces.

It is'not necessary in all cases to employ the extension flaps 2lb and 22b on the closure element. The provision of these flaps, however, is preferable as otherwise the pressure elements are likely to become unduly coated with the ther-' moplastic substance from the liner, particularly after a large number of containers have been sealed. ,The use of the flap extensions on the outside of the container has the additional advantage of providing a more adequate surface to carry suitable printed matter; such as trademarks-and description of contents. In addition,

the edge construction as herein described provides a' very sturdy container and it is possible,

due to the use of this construction, to employ a relatively lighter paperboard than would otherwise be possible or appropriate.

In lieu of applying a liner sheet to the tray blank prior to folding to tray form, it is contemplated that thermoplastic or other suitable lining material in liquid form maybe introduced or applied upon the interior of the tray prior to or after same has been set up.

From the foregoing it is apparent that a very sturdy and effective form of container is provided that can be filled and sealed with a minimum of eifort, providing an hermetically sealed construction that is well adapted for the pack-'- -aging of frozen food products. Due to the pmvision of both an inner and outer sealing surface the chances of the container being improperly sealed are reduced to a negligible degree.

While the present description sets forth a preferred embodiment of container construction and methods of sealing same, numerous changes may be made in the construction and method without departing from the spirit of the invention, and it is therefore desired that the present disclosure be considered in all respects as illustrative and not restrictive, reference being had to the appended claims rather than to the foregoing description to indicate the scope of the invention. w

I claim:

1. A paperboard container, comprising a rectangular tray having a bottom panel, side and end wall panels integrally connected thereto, end flaps on the ends of each of the side'wall panels adapted to be secured in fixed position relative to the end wall panel when the end and side wall panels are elevated to tray-forming position, said end flaps thus forming a part of the end wall, an extension flap on the free edge of each side wall and side wall end flap, a liner secured in unbroken relation over all of said panels and extension flaps, said extension flaps being. folded to lie a ainst the exterior surface of the container walls, the extension flaps on the side wall end,

flaps being of such length as to substantially abut each other on the exterior of the end walls of the tray, whereby, when the tray has been set up, the edges of the liner will-extend in substantially unbroken relation-around the entire upper exterior portion of the tray, a closure for the tray, said closure having a rectangular central panel, extension flaps on each of thesides and-ends of the central panel arranged to overlap the upper exterior portions of each wall of thetray, and a liner applied to the closure, said liner covering the central panel, together with. the side and end extensions thereon,iand extending over a substantial portion of the triangular area. defined between the adjacent end edges ofthe closure side and end extension flaps, whereby the closure may be assembled with the tray by securing the lined portions of the closure extension flaps against the upper exterior lined portions of the tray. f

2. A paperboard container comprising'a rectangular tray having a bottom panel, side and end wall panels integrally connected thereto, end flaps on the ends of each of the side wall panels adapted to be secured in fixed position relative to the end wall panel when the end and side wall panels are elevated to tray-forming position, said endflapsthusformingspartoftheendwalLan extension flap on thefree'edgeofeach side wall andsidewallendilapmlinersecuredinunbrob en relation overall of said'panels and extension 'flaps, said extension flaps being. folded to lie against. the exterior 'surfaceof the container walls, the-extensions on the-side wall-end flaps being of suchlensth asto substantially abut each of the tray, a closure for the tray, said closure having a rectangular central-panel, extension flaps on each of the sides and ends of the central panel arranged to overlap both the upper interiorand exterior portions of each wall of the tray, and a liner applied to the closure, said" liner covering the central panehtogether with the side and end extensionstheromand extending over a substantial portion of the triangular area 'defined between the adjacent end edges of the closure extension flaps, whereby the closure may be assembled with the tray by securing the lined, portionsof the closure extension flaps against the 'upper interior and exterior lined portions of the tray.

3. A paperboard container comprising a rectangular tray' having a bottom panel, side and end wall panels integrally connected thereto, end flaps on the ends of each of the side wall panels adapted to'be secured in fixed position relative to the end wall panel when the end and side wall panels are elevated to tray-forming position, an extension flap on the free edges of the side walls and side wall end flaps, a liner secured in unbroken relation over all of the interior surfaces of said panels and extensionfiaps, the extensions on the side wall end flaps being of such length as to substantially abut each other on the exterior of the end walls of the tray, whereby, when the tray has been set up, the liner will extend in substantially unbroken relation around the entire upper exterior ,portion'of the tray, a closurefor the tray, said closure having a rectangular central panel, extension flaps on each of the sides and ends of the central panel arranged to overlap the upper interior portions of the tray,

and a liner applied to the closure, covering the central panel, together with the side and end extensions thereon, and extending over a substantial portion of the triangular area defined between the adjacent end edges of the closure extension flaps, whereby the closure may be assembled with the tray by securing'the lined P tions of the closure extension flaps against the upper interior lined portions of the tray, portions of said liner being extended beyond the extension flaps overlapping the upperinterior portions of the tray, said liner portions being arranged to overlap the lined Upp r exterior portions of the tray to provide additional sealing areas.

4. A paperboard container comprising a rectangular tray having a bottom panel, side and end wall panels integrally connected thereto, end fiaps on the ends of each of the side wall panels adapted to be secured in fixed position relative to the end wall panel when the end and side wall panels are elevated to trayforming position, an extension flap on the free edges of the side walls and side wall end flaps, a thermoplastic -liner secured in unbroken relation over all of said panels and extension flaps, said extension flaps being folded to lie against the exterior sureach side wall and side wall end flap, a liner secured in unbroken relation over all of said panels and extension flaps, said extension flaps being foldedto lie against the exterior surface of the container walls, the extension flaps on the side wall end flaps being of such length as to substantially abut each other on the exterior of the end walls of the tray, whereby, when the tray has been set up, the edges of the liner will extend in substantially unbroken relation around the entire upper exterior portion of the tray.

6. A paperboard tray having abottom panel, side and end wall panels integrally connected thereto, end flaps on the ends of each 01' the side wall panels adapted to be secured in fixed position relative to the end wall panels when the end and side wall panels are elevated to trayforming position, said end flaps thus forming a part of the end wall, an extension flap on the free edge of each side wall and side wall end flap.

arranged to be folded down and secured to the exterior of the walls of the tray, the side walls being defined from the endflaps by score lines extending divergently outward from the corners of the bottom panel, whereby the side walls will be upwardly flared, the end flaps on the side walls being so formed as to contact in edge to edge relation on the exterior of the end wall panel when the tray has been set up and being of such length as to cause the side walls to assume-a position inclined outwardly from the vertical, a liner secured in imbroken relation over all of said panels and extension flaps, the edges of the linerbeing in substantial registration with the upper free corners or .the side wall extension flaps, whereby when these flaps are secured against the end wall panel, the edges of the liner will substantially meet each other on the exterior of the tray, the liner being secured to a part of the side wall end flaps and said liner being left unsecured over that portion of the side wall end around the entire upperexterior portion, of the tray, a closure for the tray, said closure having a rectangular central panel, extensionflaps'on each of the sidesand ends of the central panel arranged to overlap the upper-exterior portions of the container, and a thermoplastic liner'sheet applied to the elosurecovering the central panel together with the side and end extensions there on and extending over a substantial portion of the triangular area defined between theadja'cent end edges of the closure extension flaps, whereby the closure may be assembled with the tray by compressing the lined portions of the closure extension flaps against the'upper exterior lined flaps which is adjacent the end wall panel, the secured portion being restricted to a line extending from the upper free comer of the side wall end flap to the diagonally opposite corner there- ,of which is adjacent the corner of the. bottom panel, whereby the side wall and end wall panels are left free to be brought to a fully raised'position independently of the-movement of the side wall end flaps to their final position against the end wall panel.

'I. A paperboard tangular tray having a bottom panel, side and end wall panels connected thereto, end flaps on the ends of each of the side wall panels adapted to be secured in fixed position relative to the end wall panel when the end and side wall panels are elevated totray-forming position, an extension fiap on the free edge or each side wall and side wall end flap, a liner secured in unbroken relation over alloi. said panels and. extension flaps, said extension flaps being folded to lie against the exterior surface of the container such a length asto substantially abut each other on the exterior of the end wall panels, said end flaps together with the end panel jointly forming upwardly flaring end walls, the extension flaps of the side walls and side wall end flaps, such notches extending inwardly from the edges of the extension flaps'and terminating short ofthe inner edges of said flaps, whereby when the tray container comprising a recthe end panels to i'orm part of the end walls of the tray, extensionflaps on said side wall end flaps, such extension flapsbeing of a length so as to extend substantially beyond the center line of the end walls, said side wall end flaps having their upper portions cutaway so that the edges of such portions will meet centrally of the ends of the tray, extension flaps at the sides oi. the

dimension, in a direction. transversely of the blank, than the combined lengths or the side wall end flaps, whereby such side wall end flaps serve to predetermine the areas of the end walls of the tray.

9. A closure blank for a tapered tray, said blank comprising a rectangular central panel blank on the free edges of the side walls and side wall end flaps, said extension flaps being integrally connected to each other adjacent the lines of juncture of the sidewall and side wall end flaps ior an appreciable portion of the width of the extension flaps, said extension flaps being defined from each other over the remaining portions of their widths by cutting away the material of such flaps to'provide triangular shaped notches, the end wall panels being oia lesser adapted to fit closely against the interior surfaces of the sides and end walls of a tapered tray. at a level spaced downwardly 'i'rom the upper edges of the tray, an extension flap on each side and end of the central panel, each of said extension flaps having fold lines formed therein to divide the flaps into two adjacent sections extending lengthwise of the panel edges, whereby the sections adiacent the panel edges are adapted to engage the interior surfaces of the walls of a tapered tray and the sections remote from the panel edges are adapted to contact against the exterior surfaceso! the tray walls, said inner flap sections having outwardly divergent edges to cause such edges to meet at and conform to the inner corners of a tapered tray, the outer flap sections having outwardly convergent edges whereby the edges of adjacent outer flap sections are arranged so as to meet at and conform to the outer corners of a tapered tray.

- ROY E. LOWEY. 

